In this paper we present the results from an extensive comparison study of three R-tree packing algorithms, including a new easy to implement algorithm. The algorithms are evaluated using both synthetic and actual data from various application domains including VLSI design, GIS (tiger), and computational fluid dynamics. Our studies also consider the impact that various degrees of buffering have on query performance. Experimental results indicate that none of the algorithms is best for all types of data. In general, our new algorithm requires up to 50 fewer disk accesses than the best previously proposed algorithm for point and region queries on uniformly distributed or mildly skewed point and region data, and approximately the same for highly skewed point and region data.